Table of Contents
Journal of Metallurgy
Volume 2011 (2011), Article ID 639283, 6 pages
http://dx.doi.org/10.1155/2011/639283
Research Article

Influence of Partial Replacement of Nickel by Nitrogen on Microstructure and Mechanical Properties of Austenitic Stainless Steel

1Steel and Ferroalloys Department, Central Metallurgical Research and Development Institute, Helwan 11421, Egypt
2Physics Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo 11884, Egypt

Received 4 August 2011; Accepted 31 August 2011

Academic Editor: Gerhard Sauthoff

Copyright © 2011 A. Ahmed et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A new modified austenitic stainless steel has been developed through partial replacement of nickel by nitrogen. Nitrogen stainless steel was produced in 10 kg induction furnace under nitrogen pressure, while reference one, AISI 316 steel grade, was produced in open-induction furnace. Both were cast and hot forged, and the total nitrogen was determined. Furthermore, the produced forged steels were subjected to solution treatment at different temperatures. The microstructure of produced stainless steels was observed. The X-ray diffractmeter and Mossbauer effect spectroscopy were used to follow the phase change in reference and modified steels after different heat treatment temperatures. The influence of grain-size, soluble, and insoluble nitrogen on tensile strength and hardness was investigated. The major phase in the modified steel has a fcc structure similar to the reference one, but with finer grains and more expanded lattice. The yield strength and hardness of the nitrogen-modified stainless steel are higher than the reference steel. On the other hand, the increase of nitrogen content deteriorates the steel ductility.